"use client";

import { useState, useEffect, useMemo } from "react";
import { calculateCountdown } from "@timetoleave/core";

interface ClockResult {
  countdown: ReturnType<typeof calculateCountdown>;
  status: "upcoming" | "now" | "past";
}

export function useClock(targetDate: Date, departureTime?: Date | null): ClockResult {
  const [now, setNow] = useState<Date>(new Date());

  useEffect(() => {
    const interval = setInterval(() => {
      setNow(new Date());
    }, 10_000);

    return () => clearInterval(interval);
  }, []);

  const effectiveTarget = departureTime ?? targetDate;

  return useMemo(() => {
    const countdown = calculateCountdown(effectiveTarget);
    const diffMs = effectiveTarget.getTime() - now.getTime();

    let status: "upcoming" | "now" | "past";
    if (diffMs <= 0) {
      status = "now";
    } else if (diffMs <= 10 * 60 * 1000) {
      status = "now";
    } else {
      status = "upcoming";
    }

    return { countdown, status };
  }, [effectiveTarget, now]);
}